Abstract: Reverse micellar system consisting of the surfactants cetyltrimethyl ammonium bromide (CTAB) and Tween-60 in dissolved in n-butanol-isooctane mixture was used for α-amylase purification by reversed micellar extraction. Extraction efficiency of α-amylase was investigated under different extraction conditions using a reverse micellar phase consisting of 4 g/L (CTAB ＋Tween-60, 2.0:1.0, n/n) in n-butanol-isooctane mixture (1.0:1.0, V/V) and an aqueous phase made up of crude α-amylase solution containing 0.04 mol/L NaCl. The extraction efficiency of α-amylase was 91% when the extraction temperature, ratio of organic phase to aqueous phase and oscillation time were 40 ℃, 2.0:1.0 and 10 min, respectively. The reverse extraction efficiency of α-amylase was 65% after 10 min oscillation at 50 ℃ when the aqueous phase was comprised of aqueous phase and organic phase at a ratio of 1.0:2.0 (V/V) at pH 4.5 containing 2.5 mol/L NaCl. The reverse micelles could be repeatedly used and the extraction efficiency of α-amylase at an aqueous phase-to-organic phase ratio of 1.0:2.75 remained 71% in the second use.

Key words: cetyltrimethylammonium bromide (CTAB), Tween-60, reverse micelle, α-amylase, extraction